Multiradio mobile devices typically include several different wireless subsystems that enable the use of diverse mobile services, such as the communication of voice, data, and images over diverse wireless networks. Examples of such diverse wireless networks include mobile telephony networks (e.g., Universal Mobile Telecommunications System (UMTS), Global System for Mobile Communication (GSM)), wireless local area networks (WLANs) and WiFi networks, and piconets (e.g., Bluetooth). An example multiradio device may have one radio for voice (or combined voice/data) service over a traditional cellular network and another radio for data communications over another network (e.g., WLAN). A multiradio device may have a WLAN radio for communication with a WLAN access point, a Bluetooth radio for communication with a Bluetooth enabled printer or headset, and a traditional voice service over a cellular telephone radio. A multiradio device may have a GSM radio and a digital video broadcast for handhelds (DVB-H) radio. A multiradio device may have more than one radio for communicating over different cellular telephone networks, such as a mobile telephone having two cellular radios for use with different types of networks in different countries.
Software Defined Radio (SDR) is typically a multiradio mobile device that is controlled by embedded control software. Some of the hardware components of a multiradio device may have their characteristics adjusted by SDR control software. The tuning capabilities in an example SDR may include RF band, RF bandwidth and channel bandwidth. Also, performance related parameters, such as gain and output power affecting for example noise and linearity may be tuned by control software making adjustments to hardware components to accommodate different wireless protocols and different radio conditions.
Cognitive radio is an intelligent wireless communication system that can be based on software-defined radios, which monitors the environment and adapts to variations in input signals, to improve the reliability of communication and the efficient use of the radio spectrum. When a user requests a task, such as a voice call, a data download, location tracking etc., the cognitive radio may aid the selection of the most suitable technology, such as GSM, WLAN, Bluetooth, or the like. Cognitive radio may more efficiently use the radio spectrum because a mobile device may scan the environment, determine the best or preferred frequency band and transmission standard, and indicate its preferences by signaling other cognitive radio devices with its preferred transmit power, channel equalization and coding scheme.